ASC 606 Revenue Recognition and Significant Accounting Policies Disclosures - Disaggregation of Revenue (Details) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation Of Revenue [Line Items]
Total revenue	$ 44,380,219	$ 37,507,244	$ 91,860,475	$ 71,945,940
Electrical construction
Disaggregation Of Revenue [Line Items]
Total revenue	39,204,368	36,195,767	80,591,687	70,327,686
Electrical construction | Southeast
Disaggregation Of Revenue [Line Items]
Total revenue	15,478,325	15,841,543	34,829,199	27,825,088
Electrical construction | mid-Atlantic
Disaggregation Of Revenue [Line Items]
Total revenue	17,415,258	10,586,509	29,468,961	19,860,932
Electrical construction | Texas-Southwest
Disaggregation Of Revenue [Line Items]
Total revenue	5,882,764	9,208,624	15,423,685	20,489,967
Electrical construction | Other electrical construction
Disaggregation Of Revenue [Line Items]
Total revenue	428,021	559,091	869,842	2,151,699
Real estate development operations
Disaggregation Of Revenue [Line Items]
Total revenue	$ 5,175,851	$ 1,311,477	$ 11,268,788	$ 1,618,254